In the terminating of relatively high density arrangement of electrical conductors supported by a substrate, such as the dielectric material or insulation of an electrical cable, a circuit board, or some other substrate, terminals sometimes referred to as contacts are connected to the respective conductors and then a strain relief mechanism is provided. The terminals have contacting portions to connect to some external device, such an electrical connector, circuit board, etc., and to be removed from such connection. The strain relief prevents the application of force that would damage the connection between respective terminals and electrical conductors.
In the description here reference will be made to termination system. A termination system is the terminals and strain relief used to terminate one or more electrical conductors to facilitate connecting them to another member, external device, etc., such as, for example, a connector, circuit board or the like. An example of a termination system is a cable termination, which is such a system used to terminate the electrical conductors of an electrical cable. Another example of a termination system is one used to terminate the conductors of a circuit board, such as the conductors on or in such a circuit board. Reference herein to a termination assembly is indicative of the termination system in combination with the device being terminated, such as the electrical conductors of a cable, circuit board, etc. Sometimes such a termination assembly is referred to as a cable termination assembly when used to terminate the one or more electrical conductors of an electrical cable; however, such reference also is intended herein to include the terminating of the conductors of a circuit board or other device.
An example of a termination system for a circuit board is disclosed in U.S. Pat. No. 3,961,834. Examples of cable termination assemblies including a molded-on strain relief are disclosed in U.S. Pat. Nos. 4,030,799 and 4,863,402, both of which include insulation displacement connections (IDC) between respective contacts and cable conductors. Another cable termination system in the form of a clip type connector in which cable conductors are exposed, deformed, and connected to respective terminals, the area of connection being included within a molded connector/strain relief body, is disclosed in U.S. Pat. No. 4,679,870. The disclosures of the above patents are incorporated in their entirety by reference.
A number of problems have been encountered in the past when terminating the conductors of a flat flexible circuit or flat flexible cable (sometimes referred to as FFC or as a "flex" circuit), an etched circuit, and other devices in which the conductors are arranged at very close spacing and in which the dielectric material may be relatively fragile, not able to withstand high temperature, etc. For example, some dielectric (insulation) and/or adhesive materials, such as polyester, may not be able to withstand the high temperatures encountered during the plastic injection molding process by which the strain relief body is formed. Melting or other destruction of the integrity of such dielectric materials will reduce or eliminate the function of retaining the electrical conductors thereof in fixed positional relation. As a result, conductors may touch, causing a short circuit or conductors may be misaligned so that they will not properly connect with terminals intended to be attached thereto as part of the termination system. Another source of heat that may result in a releasing of the conductors from being held in fixed relative positions is the heat developed by securing the conductors and terminals, such as that generated by welding or soldering, such as bar soldering or induction soldering. Additionally, the flowing plastic or other material that are injection molded to form the strain relief body may tend to urge the conductors out of position, possibly resulting in a short circuit and/or open circuit where terminals are intended to connect with respective conductors.
To try to avoid the above problems in the past, the strain relief was attached mechanically, e.g., by adhesive, and/or was formed by potting techniques. However, these techniques required a relatively large number of steps and time to make the termination system and, therefore, was relatively expensive.
Some prior techniques for terminating electrical conductors of a cable or some other substrate usually involve one or more steps for preparing the cable/wire, one or more steps for terminating the conductors, as by connection to respective electrically conductive terminals (contacts), and subsequently protecting the connections by molding a strain relief to the cable and terminals. Sometimes the terminals have been preliminarily retained on a dielectric carrier, which is encased in the molded strain relief after corrections have been made between respective conductors and terminals.
Another disadvantage to such prior termination systems has been the relatively high profile of the termination system. Examples are presented in the above-mentioned patents. The above-mentioned problems are encountered when such processes are carried out.
With the foregoing in mind, then, it would be desirable to facilitate and/or to expedite the terminating of a multiconductor device, especially one having a relatively high density arrangement of conductors.
Also, it would be desirable to improve the yield of high density termination systems by avoiding short and/or opens, e.g., between conductors and terminals.
Further, it would be desirable to facilitate the accurate terminating use of relatively inexpensive multiconductor devices, such as FFCs, made of relatively low melting point dielectric materials.